Reward points and miles can accrue easily, but they can disappear easily, too [AP]

Citibank gave me 40,000 ThankYou points for opening a savings account.  (To add to the ThankYou points I earn from several Citi credit cards.)  I met all the requirements for earning the points - a certain amount on deposit and direct-deposit for a short period.)  When the interest rate went to near-zero about 18 months later, I closed the account.  A couple months later, I noticed that my point balance was several thousand points lower than I expected.  Several phone calls later, I found the person at Citi who told me that the points were taken away because I closed the bank account.  This person could not explain the specific number of points that were taken from me, and could not provide any fine print that said they could do this, because there wasn't any.  I cashed in all my remaining points before they could subtract any more.